(i) Field of the Invention
This invention relates to the use of namatodes for the biological control of insects. More particularly, it relates to an efficient, inexpensive method and means of shipping the namatodes to the site where they are to effect such biological control.
Romanomermis culicivorax is a mermithid nematode which can be mass produced in vivo and is now in use as a biological control agent against warm climate mosquitoes.
(ii) Description of the Prior Art
In the past, the transportation of the nematode eggs was in a composition formulated in sand. This made the control agent expensive because the ratio of sand to nematode eggs was high and hence the relative weight of sand increased transportation costs enormously. It was also found that the sand formulations were inefficient. There could be some loss of nematodes and their eggs due to grinding mechanical damage by shifting of the sand. If condensation occurred within the plastic wrapping around the nematode eggs, the extra water could cause the eggs to hatch prematurely. As the preparasites are short lived, they undoubtedly would die before they could be used. In addition, there was a danger of fungal infection thriving in such a situation. Alternatively, the sand could dry out completely, thus completely causing death of the eggs.
It is also known that Neoaplectana carpocapsae has activity againt many insect population, including Colorado potato beetle Leptinotarsa decemlineata, Dysdercus peruvianus (Hemiptera), Tobacco budworm Heliothis virescens, Codling moth Laspayresia pomonella, Cabbage root maggot Hylemyl brassicae, European corn borer Ostrinia nubilalis, Corn earwarm Helicoverpa zea, Imported cabbage worm Pieric rapae, Pale apple leaf roller Pseudexendera mali, Winter moth Operophtera brumata, Cutworm Pseudaletia separata, Paddy cutworm Cirphis compta, Nantucket pine tip moth Rhyacionia frustrana, Sourhern pine beetle Dendroctonus frontalis, Wireworm Agriotes sp., Pear aphids, Leaf beetles, Ladybird larvae, Root fly larvae, Rice stem borer Chilo sp., White-fringed beetle Graphognathus peregrinus, Formosan termite Coptotermes formosanus, onion borer Acrolepia assectella, Hylemya spp., Pecan weevil Curculio caryae, Spodoptera frugiperda, Rice stem borer, Navel orangeworm Paramyelois transitella, Wireworms Agritoes lineatus, and Selatosomus aeneus.
The art has been faced with the problem of safety and efficiently storing and transporting the nematodes. For mermithid, e.g., Mosquito parasitic mermithids including Romanomermis culicivorax, R. nielseni, Octomyomermis muspratti, and for Blackfly parasitic mermithids including several species of Mesomermis, Hydromermis and Isomermis, the eggs need to be transported for use in the biological control of mosquitoes and blackflies. For other, particularly rhabditid, nematodes, e.g., the Breton and DD-136 strains of Neoaplectana carpocapsae and Heterorhabditis heliothidis, the infective stage of the worm would be transported for use as parasites of a wide range of agricultural and forest pests including Choristoneura fumiferana, the spruce budworm and Scolytus scolytus, the vector of Dutch Elm Disease.
These nematodes can be mass produced on a commercial scale but storing and shipping is a problem. Thus, it is known that an efficient, inexpensive method of shipping N. carpocapsae and other rhabditids is difficult to achieve. The most important aspect involved in shipping such nematodes was believed to be able to provide enough air to keep them alive en route. This was said to be achieved by plugging the containers with cotton and avoiding the use of water as a shipping medium. It was also suggested that good methods might be to place the infective stages on some inert substances (charcoal, wood chips) that could be kept moist or indeed to transport the infective nematodes within the host cadaver. However, it was known that the nematodes should be able to be removed easily from the substrate in water when ready for application.